The cross-linked polyethylene (PEX) tubings offer a series of advantages, such as good mechanical resistance, good temperature resistance, as well as good elastic memory, among others.
Consequently, the connection of PEX tubings with fittings is used in an intensive manner in a series of industries. However, the PEX tubing is of a semi-rigid nature, on account of the connection systems used to connect them with the fittings require that the clamps are capable of applying a considerable force that is stronger than that used for connection to flexible hoses and other types of flexible pipes.
Additionally, it is important to note that, in order to comply with industrial regulations, the standards that should be satisfied are that the connections involving PEX tubings require that the same adequately resist, for example, a continuous operation for 1000 hours constraining water to a temperature of 80° C. and a pressure of 0.7 MPa (100 PSI).
In order to adequately satisfy those standards, the clamps used in the PEX connection should be capable of exerting a quantity of forces within a delimited range. In fact, if the force that the clamp exerted were to be slightly lower than the optimal value, the connection would remain loose, which would impede correct performance of the same (and would not pass the demanding standards previously mentioned). On the contrary, if the force exerted by the clamp were to be slightly higher than optimal value, the connection elements (PEX tubing and polymeric material fittings) would remain subjected to an excessive force that would also impair its performance (since its operational life would be shorter due to material fatigue which would also prevent that it passes the demanding standards previously indicated).
Due to the aforementioned, currently only metal clamps are typically used to connect PEX tubings with fittings, which involves relatively higher costs due to, on one hand for the cost of the metal, and on the other hand to the fact that they require special tools and/or a careful installation that guarantees that the clamps exert an optimum compression (no more and no less).
Additionally, it is important to note that among the systems that use metallic clamps, only the “Oetiker” type of system (for example see documents U.S. Pat. Nos. 4,003,238 and 4,315,348) has proven to be consistently capable of generating a suitable compression in its clamps, although it requires on one hand, the use of a special (and costly) tool, and on the other hand generates a permanent deformation on the clamp that is transmitted to the tubing.
However, due to the aforementioned, these metallic clamps do not allow that the connection can be disassembled (in the case that it is required to modify it) since during the installation process both the clamp and the tubing suffer high deformation levels that impair reuse.
Notwithstanding the aforementioned, among Prior Art there are connection systems for tubings that involve plastic clamps, although none of these allows generation of a sufficiently strong compression and within a sufficiently delimited range such as to be used in the connection of PEX tubings with their respective fittings.
The document U.S. Pat. No. 3,605,200 reveals a connection system that involves tubular elements and reveals a clamp defined by an arched sidewall, which has clenching elements arranged within the ends that are defined by multiple hooks, which can define multiple levels of compression. Additionally, this document reveals a triple annular flange on the internal surface that is fixed against the hose in a connected position. However, it is important to that this document does not reveal the possibility of disconnecting the clamp. On the other hand, the multiple hooks define multiple clamping positions, which complicates this connection system's ability to consistently reach an optimum pressure (within a delimited range).
The document U.S. Pat. No. 3,925,851 reveals a connection system that involves plastic hoses and a clamp defined by an arched sidewall wherein the ends have arranged clenching elements that are defined by multiple hooks, which can define multiple compression levels. Additionally, this document reveals an annular flange, with a section in a “V,” on its inner surface that is fixed against the hose in a connected position. However, it is important to note that this document does not reveal the possibility of disconnecting the clamp. On the other hand, the multiple hooks define multiple clenching positions, which hinders that this connection system can consistently reach an optimum compression (within a delimited range).
On the other hand, in Prior Art there are known systems to support tubings to sidewalls, roofs or other surfaces, that have no relation with a connection system (since these are simply systems for tubing support). With respect to those support systems it is very important to note that they are not oriented in any case to exert such a high pressure as is required in a connection system.
The document U.S. Pat. No. 4,291,855 reveals a support system of tubings that reveal a supporting element defined by an arched sidewall wherein the ends have arranged clenching elements defined by a single hook. However, the compression that this supporting element exerts is clearly low since it does not completely embrace the tubing (which impedes a strong compression). On the other hand, this supporting element can be disconnected because, on one hand, the compression that is exerted is very low (therefore separation of the hooks is not difficult) and on the other hand, there is a significant separation between the superior hook (81) and the element that limits its movement (12) which permits that a screwdriver (or similar) may be introduced (in the separation) to create a disconnection lever.
However, this significant separation would create a serious problem should this element be wanted to be used in a clamp of a connection system since this clamp (due to the significant separation) would not be capable of effectively impeding an excessive compression during installation. The aforementioned, would clearly be detrimental to the performance of the connection since, as the compression involved is very high, any excessive compression would harm both the tubing and the additional connection elements (as mentioned above).